Morphometric and anatomic characteristics of pronator quadratus muscle.

PURPOSE: In surgical procedures commonly employed for the management of scaphoid and distal radial fractures, the incision and dissection of the pronator quadratus muscle play a pivotal role. Nevertheless, comprehensive investigations into the anatomical intricacies of the pronator quadratus muscle have been relatively scarce within the clinical community. In light of this, our study endeavors to make a substantive contribution to the medical literature by conducting a meticulous examination of the morphology and morphometry of this muscle. METHODS: This study is a cross-sectional observational study conducted on 22 cadaveric upper extremities (44 sides) preserved between January 2005 and December 2018 at Istanbul University. The study included specimens with intact dissection areas and no prior surgical intervention. Observations focused on the morphometry of the pronator quadratus muscle and related anatomical structures. Statistical analysis was performed using SPSS v23.0, employing Student's t-test and paired t-test, with significance set at p < 0.05. RESULTS: Significant differences were found in the morphometric measurements of the pronator quadratus muscle between the right and left upper extremities, particularly in the vertical distance between the proximal and distal attachment points of the pronator quadratus to the radius (p = 0.008). Additionally, significant differences were observed between male and female samples for radius length (p < 0.001), ulna length (p < 0.001), pronator quadratus width (p < 0.001), and the vertical distance between pronator quadratus attachment points on both the radius (p = 0.001) and ulna (p = 0.001). Furthermore, significant correlations were identified between radius length and parameters such as the vertical distance between pronator quadratus attachment points on both the radius (p = 0.002) and pronator quadratus width (p = 0.03), and between ulna length and parameters including the vertical distances on the radius (p = 0.001) and ulna (p = 0.024). CONCLUSION: In light of our comprehensive analysis, which encompasses not only the anatomical features of the pronator quadratus muscle but also its vascular supply and the organization of its neurovascular structures, we posit that our study holds significant implications for the field of orthopedic surgery. We anticipate that this research will furnish valuable insights that can inform and enhance orthopedic procedures.

Entrenamiento microneuroquirúrgico en el espécimen anatómico. Propuesta de un plan estructurado de disección endoscópica y microquirúrgica basicraneal durante la residencia / Microneurosurgical training in the anatomical specimen: A structured plan for endoscopic and microsurgical skull base training during the residency

Antecedentes y objetivo: El desarrollo de una elevada capacidad crítica y competencia técnica constituye uno de los objetivos principales de todo programa de formación en Neurocirugía. Por múltiples factores, esta adquisición progresiva de habilidades técnicas puede resultar compleja durante la residencia. A pesar de su elevado coste y necesidad de infraestructura, existe un interés renovado respecto al papel de los laboratorios de anatomía. El estudio y disección del espécimen anatómico ha sido el contexto donde muchos neurocirujanos han desarrollado y perfeccionado la técnica microneuroquirúrgica. Proponemos un plan estructurado de disección y entrenamiento endoscópico y microquirúrgico que permita al residente obtener el máximo provecho durante su estancia en un laboratorio.Material y métodosDurante los meses de septiembre, octubre y noviembre de 2021 se realizó una estancia en el Laboratorio de Microneurocirugía y Base Craneal de la Universidad Miguel Hernández de Alicante. Se emplearon un total de 2 especímenes formolados e inyectados con silicona roja y azul. En el primer espécimen se realizó una primera fase de disección endoscópica endonasal. Tras completar la fase endonasal se plantearon un conjunto de incisiones para realizar los abordajes transcraneales. En el segundo espécimen se realizó primero la parte transcraneal dejando el trabajo endoscópico endonasal para la segunda fase.ResultadosSe muestran los resultados de la disección de los 2 especímenes. Durante la fase endoscópica endonasal se simuló el abordaje transesfenoidal a la silla incidiendo sobre los abordajes extendidos en el plano sagital. Durante la fase transcraneal se realizaron abordajes anterolaterales derecho e izquierdo, un abordaje interhemisférico transcalloso anterior izquierdo, un abordaje posterolateral transcondilar izquierdo y un abordaje lateral derecho combinado. (AU)

Background and objective: The development of a high level of competence and technical proficiency is one of the main objectives of any neurosurgical training program. Due to many factors, this progressive skill development can be complex during the residency. Despite its high cost and infrastructure requirements, there is renewed interest regarding the role of anatomy labs. The study and dissection of the human cadaver has been the environment where many surgeons have developed the necessary skills for microneurosurgery. We propose a structured endoscopic and microsurgical training dissection program to enable residents to maximize the benefits of their training in the lab.Material and methodsDuring the months of September, October and November 2021, a stay was done at the Microneurosurgery and Skull Base Laboratory of the Miguel Hernández University of Alicante. A total of 2 specimens were used. The first specimen underwent a first endoscopic endonasal dissection phase. After completing the endonasal part, a set of incisions were made to perform the transcranial part. In the second specimen, the transcranial part was performed first, leaving the endonasal endoscopic work for the last phase.ResultsThe results of the dissection program are presented. During the endonasal endoscopic phase, the transsphenoidal approach to the sella was simulated while focusing on the extended approaches in the sagittal plane. During the transcranial phase, right and left anterolateral approaches, a left anterior transcallosal interhemispheric approach, a left transcondylar posterolateral approach and a combined right lateral approach were performed. (AU)

Microneurosurgical training in the anatomical specimen: A structured plan for endoscopic and microsurgical skull base training during the residency.

BACKGROUND AND OBJECTIVE: The development of a high level of competence and technical proficiency is one of the main objectives of any neurosurgical training program. Due to many factors, this progressive skill development can be complex during the residency. Despite its high cost and infrastructure requirements, there is renewed interest regarding the role of anatomy labs. The study and dissection of the human cadaver has been the environment where many surgeons have developed the necessary skills for microneurosurgery. We propose a structured endoscopic and microsurgical training dissection program to enable residents to maximize the benefits of their training in the lab. MATERIAL AND METHODS: During the months of September, October and November 2021, a stay was done at the Microneurosurgery and Skull Base Laboratory of the Miguel Hernández University of Alicante. A total of 2 specimens were used. The first specimen underwent a first endoscopic endonasal dissection phase. After completing the endonasal part, a set of incisions were made to perform the transcranial part. In the second specimen, the transcranial part was performed first, leaving the endonasal endoscopic work for the last phase. RESULTS: The results of the dissection program are presented. During the endonasal endoscopic phase, the transsphenoidal approach to the sella was simulated while focusing on the extended approaches in the sagittal plane. During the transcranial phase, right and left anterolateral approaches, a left anterior transcallosal interhemispheric approach, a left transcondylar posterolateral approach and a combined right lateral approach were performed. CONCLUSIONS: The structured dissection of the specimen allowed both endonasal endoscopic and transcranial microsurgical training in the same specimen. This design facilitated the realization of the core skull base approaches in the same specimen. According to our initial experience, we believe that developing common dissection programs is a powerful tool to maximize the results of our residents' laboratory training.

Fetal Development in Anatomical Preparations of Ruysch and the Meckels in Comparison.

Anatomical collections have been used for centuries for research and teaching purposes. By the example of selected preparations of fetal development from the Ruysch collection (17th-18th centuries) and the Meckel collections (18th-19th century), this article aims to trace the changing purposes, specifics and methods of creating specimens as well as the development of anatomy during that period. The selected specimens are compared and analyzed implementing the historical-critical method. Regarding the appearance of the preparations, we see a transition from the visually aesthetic specimens (Ruysch) to exact ones (Meckel collections). If Ruysch's preparations were compared in his time to works of art, specimens created by three anatomists of the Meckel dynasty were primarily created for teaching and research purposes. However, Ruysch's preparations tracing fetal circulation were scientific discoveries of the time. As for preparations of fetal development from the Meckel collections, we see both specimens of physiological processes already known at that time and experimental ones. Regarding teratology, Ruysch and Meckel the Younger tried to explain malformations, but their anatomical preparations could hardly give answers to the cause of deviations from the norm. The differences between the collections can be explained by the different stages of development of anatomy of the time and by the research interests of the anatomists themselves.

Cryodehydration protocol to obtain high-quality permanent anatomical material.

The study of anatomy is largely dependent on cadaveric specimens to fulfill the tridimensional comprehension of each structure as well as the relationship between organs. Given the difficult access to fresh anatomical specimens, the constant renovation of samples for research and educational purposes is unsustainable, beyond the ethical issues involved. The standard technique for preserving specimens involves fixation and later immersion in formaldehyde, which enables a good result, but also presents elevated carcinogenic potential. Therefore, safe and efficient preservation methods are mandatory for anatomical practices and investigations. An accessible and inexpensive alternative for specimen preservation is cryodehydration. Cryodehydrated specimens can be kept dry, with no final odor, reducing the use and exposure to formaldehyde. The objective of this study was to propose a simplified step-by-step cryodehydration protocol to obtain high-quality anatomical specimens. Through consecutive freezing and thawing cycles, cryodehydration caused a weight reduction of 60%-70% and allowed anatomical preservation, while maintaining the main morphological aspects of cavitary and parenchymatous organs, muscles, or even full-body sections. The final specimens presented high durability and can be maintained for decades, preserving all relevant anatomical features.

A bigger suture diameter for anterior cruciate ligament all-inside graft link preparation leads to better graft stability: An anatomical specimen study.

BACKGROUND: In anterior cruciate ligament reconstruction, different suture types are used for graft link preparation. Thus the aim of this study was to determine whether differences in the diameter of the suture used influence biomechanical stability of the prepared graft. We hypothesized that the use of a greater suture diameter leads to a higher load to failure rate in tested graft links. METHODS: In an anatomic specimen study, ligament preparation was enrolled in 15 cadaveric knees. The material used was the semitendinosus/gracilis tendon, which was fresh frozen (-80°) after harvesting for four weeks. The grafts were then defrosted, randomized into two groups and prepared with the same technique: 12 with a suture; FiberWire No. 2 and 12 with a FiberWire No. 0. RESULTS: Overall, the group using FiberWire No. 2 presented with a mean load to failure rate of 730.67N, mean overall final elongation of the graft was 5.98mm. In the FiberWire No. 0 group mean load to failure was with a mean overall elongation of the graft of 6.96mm. Significant differences (P=0.006) between the two groups with regard to the load to failure rate were found, with FiberWire No. 2 withstanding forces better. There was no difference in elongation of the grafts or mode to failure between the two groups. CONCLUSIONS: Graft preparation with a bigger suture type is recommended to gain better load to failure rates, also in smaller-diameter grafts. Regarding the elongation rate, different suture types did not influence the outcome. LEVEL OF EVIDENCE: Anatomical specimen study, Level III.

Frederik Ruysch (1638-1731): Historical perspective and contemporary analysis of his teratological legacy.

The Peter the Great Museum of Anthropology and Ethnography (Kunstkamera) in Saint Petersburg is the oldest museum in Russia. It keeps the remains of the anatomical collection of the world-famous 17th century Dutch anatomist Frederik Ruysch. This unique collection was bought and shipped in 1717 by Czar Peter the Great, and presently still comprises more than 900 specimens, a modest number of which concerns specimens with congenital anomalies. We searched for teratological clues in the existing collection and in all his descriptions and correspondence regarding specimens and cases he encountered during his career as doctor anatomiae and chief instructor of the surgeons and midwives in Amsterdam. A total of 63 teratological specimens and case descriptions were identified in this legacy, including some exceedingly rare anomalies. As it turns out, Ruysch was the first to describe several of the conditions we encountered, including intracranial teratoma, enchondromatosis, and Majewski syndrome. Although his comments pose an interesting view on how congenital anomalies were scientifically perceived in early 18th century Europe, Ruysch mostly refrained from explaining the causes of the conditions he encountered. Instead, he dedicated himself to careful descriptions of his specimens. Almost 300 years after his demise, Ruysch's legacy still impresses and inspires both scientists and lay men. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.